Method of measuring the volume of toner consumed in printer and apparatus therefor

ABSTRACT

A method and apparatus for measuring the volume of toner consumed in a printer using a beam modulation technique, wherein: printing data, which is input in units of multiple numbers of bits per pixel in synchronization with a video clock signal, is converted into bit values corresponding to equal sections into which each pixel is divided depending on the number of bits per pixel. Next, a carry value is obtained by summing the bit values corresponding to the number of converted sections of printing data with the previous bit value. Then, the carry value obtained in this manner is counted. The counted carry value is multiplied by a predetermined value, and the volume of toner consumed is measured using the resulting product.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method and apparatus formeasuring the volume of toner consumed in a printer and, moreparticularly, to a method and apparatus for measuring the volume oftoner consumed in a printer adopting a video data modulation technique.

[0003] This application is based on Korean Patent Application No.2001-835, filed Jan. 6, 2001, which is incorporated herein by referencein its entirety.

[0004] 2. Description of the Related Art

[0005] As shown in FIG. 1, a printer 102 is typically connected to acomputer 101 via a communications interface 103. The computer 101transmits data made by a user to the printer 102 via the interface 103,and the printer 102 internally processes received data and prints theprocessed data. Here, reference numeral 101 a denotes an applicationprogram, reference numeral 101 b denotes a printer driving program,reference numeral 102 a denotes a printer controller board, referencenumeral 102 b denotes a printer engine, and reference numeral 102 cdenotes a manipulation panel.

[0006] In the prior art, a printer as described above adopts a sensor(not shown) to measure the volume of toner consumed. However, thisprinter is required to take remedial measures due to a lack ofreliability and accuracy of the sensor that cause the malfunction of thesensor and/or difficulties with the use of the sensor. Consequently, atechnique for counting a number of printing data that synchronizes witha video clock and for informing the system of a state of “tonerexhaustion” when the counted value reaches a predetermined referencevalue has been developed.

[0007]FIG. 2 is a block diagram schematically illustrating the structureof a conventional apparatus for measuring the volume of toner consumed,which adopts the aforementioned technique. Referring to FIG. 2, aconventional data required amount calculating apparatus 200 is made upof a count effective signal generation unit 201, a counting unit 202 anda total counted value and reference value storage unit 203. The counteffective signal generation unit 201 receives video printing data and avideo clock signal VCLK for synchronizing the print data from thecomputer 101 and generates an effective signal. Here, the video printingdata and the video clock signal VCLK are generated by the printercontroller board 102 a. The counting unit 202 counts the number ofpulses of a generated effective signal and calculates the number ofvideo printing data actually required to print one page. The storageunit 203 accumulates counted values.

[0008] When a printer adopting the conventional data required amountcalculating apparatus 200 having such a structure prints a pixel, theeffective signal generation unit 201 generates an effective signal inwhich printing data keeping a value of 1 exists within a video clock.Then, the counting unit 202 counts the number of pulses of an effectivesignal generated while one page is being printed. Finally, the printercontroller board 102 a compares the accumulated value with a referencevalue and measures the volume of toner consumed.

[0009] In this conventional method of measuring the volume of tonerconsumed, the count effective signal generation unit 201, which is anAND gate, combines the bits of printing data. Thus, this conventionalmethod is suitable for printers in which printing data is capable ofexpressing only two values, 0 and 1, and is allocated for a pixel thatcan be a barometer of the resolution, and then printed. However, in theevent that the number of bits of received printing data changes to 8bits, 4 bits and 2 bits in order to improve the quality of image, inparticular, in the event of beam modulation (video data modulation)printers, this conventional method cannot accurately calculate theprinting data that is actually required, and, consequently, cannotaccurately measure the volume of toner consumed.

SUMMARY OF THE INVENTION

[0010] To solve the above problems, an objective of the presentinvention is to provide a method of measuring the volume of tonerconsumed, by which the volume of toner consumed can be accuratelymeasured by calculating the exact volume of printing data actuallyrequired even when a multiple printing data value is allocated to onepixel, as in beam modulation printers.

[0011] Another objective of the present invention is to provide anapparatus for measuring the volume of toner consumed, which adopts theparticular toner consumed volume measuring method in use by the printer.

[0012] To achieve the first objective, the present invention provides amethod of measuring the volume of toner consumed in a printer, themethod including the steps of: (a) converting printing data, which isinput in units of multiple bits per pixel in synchronization with avideo clock signal, into bit values corresponding to equal levels intowhich each pixel is divided depending on the number of bits; (b)generating a carry value by summing the bit values corresponding to thelevels of printing data converted in step (a) with the previous bitvalue; (c) counting the carry value generated in step (b); and (d)multiplying the counted value obtained in step (c) by a predeterminedvalue and measuring the volume of toner consumed using the resultingproduct.

[0013] To achieve the second objective, the present invention providesan apparatus for measuring the volume of toner consumed in a printer,the apparatus including: a buffer control unit for converting printingdata, which is input in units of multiple bits per pixel, insynchronization with a video clock signal, into bit values correspondingto equal sections into which each pixel is divided depending on thenumber of bits; a summing register for generating a carry value bysumming the bit values corresponding to the sections of printing dataconverted by the buffer control unit and a pre-stored bit value; acounting unit for counting the carry value generated by the summingregister, thus generating a counted value; a multiplier for multiplyingthe counted value obtained by the counting unit by a predeterminednumber, thus obtaining a counted value product; a counted value storageunit for storing the counted value product; and a microcomputer forsetting the counted value product to be a value for measuring the volumeof toner consumed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above objectives and advantage of the present invention willbecome more apparent by describing in detail a preferred embodimentthereof with reference to the attached drawings, in which:

[0015]FIG. 1 is a block diagram schematically illustrating the structureof a printer that is typically connected to a computer;

[0016]FIG. 2 is a block diagram schematically illustrating the structureof a conventional apparatus for measuring the volume of toner consumed;

[0017]FIG. 3 is a signal waveform view of printing data and a videosynchronization clock signal that are input to the count effectivesignal generation unit of FIG. 2;

[0018]FIG. 4 is a block diagram schematically illustrating the structureof an apparatus for measuring the volume of toner consumed in a printeraccording to the present invention;

[0019]FIG. 5 is a waveform view of printing data which is received bythe data buffer control unit of FIG. 4 and divided into equal partsdepending on the number of bits in each pixel;

[0020]FIG. 6 is a conceptual diagram illustrating the arithmeticoperation of the data buffer control unit and the summing register ofFIG. 4; and

[0021]FIG. 7 is a flowchart for illustrating a method of measuring thevolume of toner consumed in a printer according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] Referring to FIG. 4, a printer for measuring the volume of tonerconsumed, according to the present invention, is made up of a printvideo controller 400 and a printer engine 430. The printer engine 430generates a video clock signal VCLK and a printing synchronous signalPSYNC and applies them to a data modulation unit 420 in the print videocontroller 400.

[0023] The print video controller 400 is made up of a counted valuegeneration unit 410 and the data modulation unit 420. The counted valuegeneration unit 410 is made up of a buffer control unit 403, a summingregister unit 404, a counting unit 405, a multiplying unit 406, acounted value storage unit 407, and a clock generation unit 408.

[0024] In the counted value generation unit 410, the clock generationunit 408 receives a video clock signal VCLK from the printer engine 430and generates a clock signal for requesting printing data from anexternal computer. The buffer control unit 403 stores first printingdata (Y bits) made up of several pixels, each of which has a pluralityof bits (X bits), in a buffer (not shown) in response to the video clocksignal VCLK and the printing synchronous signal PSYNC received from theprinter engine 430, and converts the first printing data into secondprinting data (X bits) by dividing the first printing data into equalparts each having a number of bits equal to the number of bits in eachpixel (X bits). The buffer control unit 403 outputs the second printingdata to the data modulation unit 420. Here, the first printing data canbe data having a variable number of pixels, such as 1-pixel data,2-pixel data, 4-pixel data, 8-pixel data, 16-pixel data or the like. Thesecond printing data has a number of bits, which are equal to the numberof bits in each pixel, such as, 1 bit, 2 bits, 4 bits or 8 bits. Thesumming register unit 404 sums the bit value for the second printingdata generated by the buffer control unit 403 and the bit value storedin itself in response to the video clock VCLK and the printingsynchronous signal PSYNC received from the printer engine 430, and thengenerates a carry. At this time, the summing register unit 404 storesthe sum until a subsequent instance of second printing data is received,and outputs a carry value obtained by using the most significant bit asa carry to the counting unit 405. Also, the summing register unit 404adds 1 upon the next summation in order to compensate for a loss valueof 1, which is generated every time the carry value is changed. Thecounting unit 405 increases a count value by 1 whenever the carry valuegenerated by the summing register unit 404 is 1. The multiplying unit406 multiplies the count value of the counting unit 405 since tonerexhaustion or use continues even when the carry value changes from 1 to0. The counted value storage unit 407 stores the product of the countedvalue multiplied by the multiplying unit 406. The microcomputer (notshown) measures the volume of toner with reference to the counted valueproduct stored in the counted value storage unit 407.

[0025] The data modulation unit 420 receives the second printing dataoutput from the buffer control unit 403 and outputs values modulated inaccordance with 2^(X) (where the superscript power X denotes the numberof bits in each pixel) levels in the form of video data (VD) to theprinter engine 430 in response to the video clock signal VCLK and theprinting synchronous signal PSYNC.

[0026] Referring to FIG. 5, the second printing data VD is partitionedinto 2^(X) equal sections in one pixel period in synchronization withthe video clock signal VCLK, and the divided 2^(X) equal levels areoutput for corresponding pulse durations. The value of the bits ismeasured as the volume of toner for a pixel.

[0027] Referring to FIG. 6, received first printing data, the number ofbits of which is variable, is stored in a buffer 601 in the buffercontrol unit 403 and converted into second printing data having as manybits as the number of bits in each pixel. The bits of the secondprinting data are summed with the bits stored in a summing register 602in the summing register unit 404. The buffer 601 in the buffer controlunit 403 has X bit places and stores second printing data. The summingregister 602 has (X+1) bit places, the number of which is one more thanthe number of bits of the second printing data, and stores the sum ofthe preceding second printing data. Thus, the summing register 602 sumsthe bits (X bits) stored in the buffer 601 and the (X+1) bits of thesumming register 602 at the first video clock VCLK, stores the sumwithout change, and uses the (X+1)th bit place as a carry bit. At thesecond video clock VCLK, the summing register 602 sums thecurrently-stored bit value and the second printing data input at thesecond video clock VCLK and stores the sum in itself. Whenever aresultant value greater than the X-th bit is generated upon summation,the value of the carry bit, the (X+1)th bit, alternates between 0 and 1,and the converted carry bit is output to the counting unit 405.

[0028] The bit values summed by the summing register 602 are againsummed with the bit value of the second printing data output from thebuffer control unit 403 at every continuous video clock VCLK to generatea carry value, as described above. The carry value generated in thisprocess repeatedly alternates between 0 and 1, and is a barometer formeasuring the volume of toner of a video clock signal (VCLK)corresponding to one pixel. Whenever the carry value toggles between 0and 1, a loss value is generated. In order to compensate for the lossvalue, 1 is added at the next video clock whenever the carry valuetoggles.

[0029]FIG. 7 is a flowchart for illustrating a method of measuring thevolume of toner consumed in a printer according to the presentinvention. First, the printer engine 430 is driven, in step 710, and aprinting synchronous signal is detected, in step 720.

[0030] Next, when a printing synchronous signal is generated by theprinter engine 430 and detected, the buffer control unit 403, thesumming register 404, and the clock generation unit 408 are reset, instep 730. The clock generation unit 408 is used as a printing datarequest clock.

[0031] Then, printing data input in multiple numbers of bits insynchronization with the printing data request clock are stored in thedata buffer control unit 403, in step 740.

[0032] Thereafter, the buffer control unit 403 converts the printingdata input in synchronization with a video clock VCLK, into printingdata whose each pixel is divided into 2^(X) (where X denotes the numberof bits in each pixel) levels, in step 750.

[0033] Then, the summing register 404 generates a carry by summing thecurrent bit value of printing data received in synchronization with thevideo clock signal VCLK with the previous bit value, and keeps the sumuntil the bit value of the next instance of printing data is received,in step 760. Here, the bit of the carry is not converted until the carryvalue reaches at least a value defining the full volume of tonerconsumed corresponding to a video clock. The generated carry value iscounted by the counting unit 405, in step 770. The counting unit 405should count the volume of toner corresponding to a video clock evenwhen the carry value is 0, but counts the carry value only when thecarry value is 1. Thus, to compensate and correct the counted value, thecounting unit 405 doubles the carry value, thus generating a countedvalue product.

[0034] Then, the counted value product (doubled counted value) isaccumulated in the counted value storage unit 407, in step 780.

[0035] Thereafter, the above-described steps are repeated until printingis concluded, in step 790.

[0036] Therefore, the counted value product stored in the counted valuestorage unit 407 is used to measure the total volume of toner consumedduring printing.

[0037] As described above, the present invention measures the volume oftoner consumed by receiving multiple-bit printing data instead ofprinting data made up of a fixed number of bits. Thus, the presentinvention measures toner use without requiring a sensor.

[0038] Although the invention has been described with reference to aparticular embodiment, it will be apparent to one of ordinary skill inthe art that modifications of the described embodiment may be madewithout departing from the spirit and scope of the invention. That is,the present invention can be applied to all types of printers that usebeam modulation.

[0039] According to the present invention as described above, printingdata having several pixels, each of which has a multi-bit informationvalue, is output as printing data having as many bits as the number ofbits in each pixel, and then printing data actually required isaccurately calculated by continuous bit summing of the equal sections ofprinting data. Thereby, the volume of toner consumed is accuratelymeasured.

What is claimed is:
 1. A method of measuring the volume of tonerconsumed in a printer, the method comprising the steps of: partitioningprinting data having units of multiple pixels, into parts, each parthaving as many bits as a number of bits in each pixel, said partitioningperformed in synchronization with a video clock signal; generating acarry value by summing the bits of a corresponding one of the parts intowhich the printing data is partitioned with the bits of a previous part;and counting the generated carry value to obtain a counted value.
 2. Themethod of claim 1, further comprising the step of adding 1 at a nextvideo clock signal in order to compensate for a loss value which isgenerated when the carry value toggles at a prior video clock signal. 3.The method of claim 1, further comprising the step of multiplying thecounted value by a predetermined value and measuring the volume of tonerconsumed using the resulting product.
 4. The method of claim 1, whereineach pixel of the printing data is divided into 2^(X) equal sections inthe step of partitioning, X being the number of bits in each pixel. 5.The method of claim 1, further comprising the step of doubling thecounted value.
 6. An apparatus for measuring the volume of tonerconsumed in a printer, comprising: a buffer control unit which convertsprinting data having units of multiple bits per pixel, insynchronization with a video clock signal, into bit values correspondingto equal sections into which each pixel is divided, the number ofsections varying according to the number of bits in each pixel; asumming register which generates a carry value by summing each bit valuecorresponding to the sections of printing data converted by the buffercontrol unit and a prestored bit value; a counting unit which counts thecarry value generated by the summing register, thus obtaining a countedvalue; a multiplier which multiplies the counted value obtained by thecounting unit by a predetermined number, thus obtaining a counted valueproduct; a counted value storage unit which stores the counted valueproduct; and a microcomputer which sets the counted value product to avalue for measuring the volume of toner consumed.
 7. The apparatus ofclaim 6, wherein the summing register includes bit places, the number ofbit places being at least one more than a number of bits of printingdata generated by the buffer control unit, to generate said carry value.